Silicone rubber material for soft lithography

ABSTRACT

The present invention relates to a silicone rubber like material and a printing device including a stamp layer ( 100;201 ) comprising such a material. The material is suitable for use in soft lithography as it enables stable features having dimensions in the nanometer range to be obtained on a substrate, and also allows for the accommodation onto rough and non-flat substrate surfaces. The invention also relates to methods for manufacturing the silicone rubber like material and stamp layer ( 100;201 ) and use thereof in lithographic processes.

FIELD OF THE INVENTION

The present invention relates to a silicone rubber like material and astamp layer comprising such a material for use in soft lithography. Theinvention also relates to methods for manufacturing the silicone rubberlike material and use thereof in lithographic processes and devices.

BACKGROUND OF THE INVENTION

In recent years, techniques for designing micrometer sized structures inelectrical, optical and photonic applications have been developed. Suchtechniques may be based on molding and contact printing, collectivelyreferred to as soft lithography.

Soft lithography typically makes use of a patterning device, such as astamp comprising a transfer surface having a well defined reliefpattern. Structures and features are formed upon conformal contactbetween the stamp transfer surface and a substrate.

In order to pattern large areas using soft lithography techniques, it iscrucial that no deformation of the patterns occurs when the stamp ishandled. Furthermore, it is critical that the stamp conforms to the“non-flatness” or roughness of the substrate. The characteristics of thestamp material are thus of special importance and may be critical.

Commonly used stamp materials include poly-di-methyl siloxane (PDMS)based materials, e.g. Dow Comings Sylgard 184. Although such materialsare capable of establishing reproducible conformal contact with asubstrate material, they are subject to problems associated withpressure induced deformations when providing very small pattern featuresin the nanometer range, e.g. in the sub 100 nm range. Moreover,conventional PDMS materials are susceptible to rounding of sharp cornersdue to surface tension, especially when features smaller than 100 nm aremolded.

One way to increase the stability of stamp materials is to increase theYoung's modulus; i.e. elasticity modulus of the material. However, anincrease in Young's modulus may result in that the material becomes toorigid, resulting in poor accommodation onto rough and non-flat surfaces.Hence, soft lithography is limited in resolution by the stamp materialused, and for large area imprint the material needs to have a Young'smodulus being high enough to generate stable features having very smalldimensions, but at the same time the material must be as soft aspossible to accommodate conformal contact on rough and non-flatsubstrates.

WO 2007/121006 discloses compositions and methods that may be used toform low thermal distortion molds. The compositions comprise a curableelastomeric silicone composition formed using a de-volatized polymer andat least one de-volatilized cross-linker. In one embodiment, thesilicone composition comprises a silicone resin and an organosiliconcompound having an average of at least two silicon-bonded hydrogen atomsper molecule and a catalytic amount of a hydrosilation catalyst.

A drawback in using silicone resins in transfer layers for lithographicpurposes is that resins are glass like with glass transitioningtemperatures ranging from room temperature to 300-400° C. The Young'smodulus of such resin materials is very high (above 100-200 MPa), whichmay prevent conformal contact, as the stamp cannot follow the micrometerand even nanometer sized roughness of a substrate. The imprinted layerforms a rigid material, and removing the stamp requires high forces.This results in that the forces on the features in the stamp andimprinted features become very high, which may result in damage of thestamp and/or the imprinted features.

Accordingly, there is a need in the art to provide a material to be usedin imprint lithography of large areas, said material being capable ofproviding patterns of nanoscale structures having high fidelity and goodmechanical robustness while maintaining good conformal contact on roughand non-flat substrate surfaces.

SUMMARY OF THE INVENTION

An object of the present invention is to at least partly overcome theabove-mentioned problems and to fulfil the need in the art.

Especially, it is an object of the present invention to provide amaterial suitable for use in a lithographic process, which material hasa high Young's modulus enabling the imprint of features in the nanometerrange, but at the same time allows for the accommodation of conformalcontact on rough and non-flat substrates.

Thus, in a first aspect, the present invention relates to a siliconerubber like material comprising at least one T branched and/or Qbranched (poly)siloxane precursor crosslinked by at least one linearpolysiloxane, wherein said material has an Young's modulus in the rangeof from 7 MPa to 80 MPa.

The material according to the invention is flexible and readily conformsto a wide variety of substrates. Furthermore, it is less susceptible todeformations caused by polymerization and curing during fabrication. Itis therefore suitable for use in stamp structures or patterning devicesto generate lithographic patterns.

The silicone rubber like material has a Young's modulus in the range offrom 7 MPa to 80 MPa. This renders the material deformable and minimizesdistortion of the relief pattern, which may occur upon formation ofconformal contact between the stamp surface and a substrate surface.

Accordingly, stable and reproducible features having sizes in thenanometer range; even below 10 nm may be obtained on a substratesurface; irrespectively of the surface being flat or roughened.

In a second aspect, the invention relates to a printing device having astamp layer comprising the silicone rubber like material according tothe invention. The printing device may be used in for example alithographic process.

The printing device may be as simple as the stamp layer comprising apattern of features.

Alternatively, the printing device may be a device having means formanipulating the stamp layer with respect to a substrate which needs tobe provided with a print of the pattern of features. Such a deviceconstitutes ad patterning device that can be used for soft lithographyapplications. It allows for the patterning device to be applied in acontrolled manner, promotes formation of conformal contact over largeareas of the substrate surface and enhances the fidelity of patternsgenerated on a substrate surface. Accordingly, the overall efficiencyand energy consumption of the patterning process is improved.

The printing device according to the invention allows for small featuresto be obtained on a substrate surface without damage or altering of thefeatures thus formed.

In another aspect, the present invention provides a method formanufacturing a silicone rubber like material having a Young's modulusin the range of from 7 MPa to 80 MPa, said method comprising:

-   -   providing a composition comprising at least one functional T        branched and/or Q branched (poly)siloxane precursor    -   adding at least one functional linear polysiloxane to said        composition    -   incubating said composition at a temperature below 100° C. to        effect crosslinking of said at least one functional T branched        and/or Q branched (poly)siloxane precursor by said at least one        functional linear polysiloxane.

This method enables a high degree of crosslinking of the T branched(poly)siloxane precursor to be effected, resulting in silicone networkstructures having flexible chains. A silicone rubber like materialhaving a Young's modulus in the range of from 7 MPa to 80 MPa canthereby be obtained, even when incubation takes place at very lowincubation temperatures; e.g. below 100° C.

In embodiments, the method comprises the step of arranging a pattern inthe silicone rubber like material. Preferably the pattern is a reliefpattern having features with their smallest lateral dimensions smallerthan 300 nm. Even more preferably they are smaller than 200 nm. Mostpreferably the dimensions are smaller than 100 or 50 nm.

This, typically, is effected by incubating the composition in step (c)on a master mold pattern to effect a stamp layer comprising a pattern offeatures.

Preferably, the composition is incubated at a temperature below 50° C.

The method according to the invention is advantageous as it does notrequire high incubation temperatures; i.e. curing temperatures.Disadvantages associated with high incubation temperatures are therebyavoided. For example, high incubation temperatures may result in thermalmismatch between a master pattern material and the stamp material. Thisis due to the build up of large stresses during heating and cooling andmay result in crack formation and damage of features.

A method according to the invention has the advantage that it isrelatively simple, inexpensive and has a high reproducibility whichmakes it suitable for mass production. The stamp layers thus formed maybe used in several types of stamp structures or patterning devices.

The term ‘T branched’ used for definition of functional T branchedpolylisoxane precursor of this application means that there is withinthis precursor at least one Silicon atom attached to three(poly)siloxane chains. Preferably this Silicon atom is chemical bound tooxygen of each of the (poly)siloxane chains.

The term ‘Q branched’ used for definition of functional Q branchedpolylisoxane precursor of this application means that there is withinthis precursor at least one Silicon atom attached to four (poly)siloxanechains. Preferably this Silicon atom is chemical bound to oxygen of eachof the (poly)siloxane chains.

The term ‘functional’ used for definition of ‘functional T branched orfunctional Q branched polylisoxane precursor’ of this application meansthat there is within this precursor at least one chemical group orsubstituent that is capable of chemical reaction under the conditions ofincubation in order to provide crosslinking with the linearpolysiloxane.

In one embodiment the at least one silicon atom bears the functionalgroup.

In another embodiment at least one of the three (T branched) or four (Qbranched) polysiloxane chains bears at least one and preferabley onefunctional group. In yet another embodiment all the three (T branched)or four (Q branched) polysiloxane chains of a branched precursor bear atleast one and preferably one functional groups.

Functional groups may be any of functional groups that are able toprovide the chemical reaction and thus crosslinking between thefunctional T branched and/or Q branched polysiloxane precursor andlinear polysiloxane.

In one embodiment the functional group is in the form of a vinyl group.

In embodiments of the invention, the at least one functional T branchedand/or Q branched (poly)siloxane precursor is selected from the groupconsisting of a hydride functional T branched and/or Q branched(poly)siloxane precursor, a vinyl functional T branched and/or Qbranched (poly)siloxane precursor and/or mixtures thereof.

The vinyl and/or hydride functionality improves and regulates the degreeof crosslinking and results in a silicone network structure. Thematerial thus formed is a highly flexible silicone rubber like materialwhich has a modulus in the range of 7 MPa to 80 MPa.

To further increase the degree of crosslinking, the at least onefunctional linear polysiloxane is selected from the group consisting ofa hydride functional linear polysiloxane, a vinyl functional linearpolysiloxane and mixtures thereof

In preferred embodiments, the at least one vinyl functional linearpolysiloxane is at least 5% vinyl functional. The percentage is to beconstrued as meaning as it means that 30% of the silicon atoms in thelinear siloxane should be hydride functional. (the same for the vinylfunctional silicon atoms)

The functional vinyl groups of the linear polysiloxane(s) react with thefunctional T branched and/or Q branched (poly)siloxane precursor(s)which allows for a large degree of crosslinking, resulting in a siliconerubber like material having a Youngs's modulus within the ranged of 7 to80 MPa.

In other preferred embodiments, the at least one hydride functionallinear polysiloxane is least 30% hydride functional.

In embodiments, the ratio of hydride functional linear polysiloxane tovinyl functional linear polysiloxane is in the range of from 2:10 to8:10.

By adjusting the proportion of hydride and/or vinyl functional Tbranched and/or Q branched (poly)siloxane precursor(s) and linearpolysiloxanes, respectively, the degree of crosslinking may be varied.This is advantageous since the Young's modulus of the silicone rubberlike material thus formed may be tuned to a desired value. The degree ofcrosslinking, and hence the Young's modulus can thereby be strictlycontrolled.

In yet another aspect, the invention relates to the use of a siliconerubber like material according to the above or obtainable by the abovedescribed method as a stamp layer for lithographic processes.

These and other aspects of the invention will be apparent from andelucidated with reference to the embodiment(s) described hereinafter

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic drawing of a printing device in the form of astamp layer according to the present invention.

FIG. 2 is a schematic drawing of a stamp structure comprising the stamplayer according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a silicone rubber like materialcomprising at least one T branched and/or Q branched (poly)siloxaneprecursor crosslinked by at least one linear polysiloxane, wherein saidmaterial has a Young's modulus in the range of from 7 MPa to 80 MPa.

As used herein the term “T branched (poly)siloxane precursor” refers toa silicone material comprising a network of oligosiloxanes, wherein oneor more silicone atoms are bound by at least three oxygen atoms to othersilicone atoms. The term “Q branched (poly)siloxane precursor” refers toa silicone material comprising a network of oligosiloxanes, wherein oneor more silicone atoms are bound by at least four oxygen atoms to othersilicone atoms.

The T branched (poly)siloxane precursor is able to form 3-way branchingchains, i.e. networks, when crosslinked by linear polysiloxanes,typically linear PDMS chains. Likewise, the Q branched (poly)siloxaneprecursor is able to form 4-way branching chains, i.e. networks, whencrosslinked by linear polysiloxanes, typically linear PDMS chains.

The resulting silicone rubber like material according to the inventionreadily conforms to a wide variety of substrates, including siliconbased materials, glasses and plastics. Thus, the material is verysuitable for use in stamp structures or patterning devices to generatelithographic patterns.

The silicone rubber like material has a Young's modulus in the range offrom 7 MPa to 80 MPa.

Hence, the material is deformable, and when used in soft lithography, ithas the ability to conform to both flat and roughened surfaces.Furthermore, it allows the provision of stable and reproducible featureshaving sizes in the nanometer range; even below 10 nm on a substratesurface.

Problems associated with rounding of sharp corner which is the case withconventional PDMS materials are thereby avoided.

When used in stamp lithography, it is crucial that the stamp materialhas the ability to deform substantially (e.g. between 2 and 100%), butreturn to the original shape when the force is removed. The siliconerubber like material according to the invention exhibits this property.Even though it has a high Young's modulus, it avoids the disadvantagesof rigid or glass like materials which may show creep and deformpermanently when forces are applied. The material according to theinvention has a rubber like behaviour and is able to cure from a liquidinto the rubber at room temperature or temperatures at which the finalstamp will be used.

Furthermore, the deformability of the material minimizes distortion ofthe relief pattern, which may occur upon formation of conformal contactbetween a stamp and a substrate and also provides a more accuratereplication of features. Hence, the inventive silicone rubber likematerial has the ability to provide stable features without resulting increep formation.

The silicone rubber like material according to the invention istypically used above its glass transition temperature.

In a preferred embodiment, the invention relates to a printing devicehaving a stamp layer 100 comprising the above mentioned silicone rubberlike material for use in a lithographic process illustrated in FIG. 1.

The stamp layer 100 comprises a plurality of relief features 101separated by a plurality of recessed regions 102. The patterned stampsurface layer also has a plurality of contact surfaces 103 arranged tocontact the surface of a substrate 104. The relief features may have anyshape desired. The smallest width of the relief features within thestamp may have dimensions in the range of 300, 200, 100, 50, and/or 25nanometer.

The modulus of the silicone rubber like material is in the range of from7 to 80 MPa. If the modulus is lower than 7 MPa, e.g. lower than 5 MPa,it is not possible to form features having sizes below 300 nm. On theother hand, if the modulus is too high, i.e. higher than 80 MPa,conformal contact may be impaired as the stamp cannot follow micrometerand nanometer sized roughness. This leads to high local stress which maydamage the stamp and the features.

A Young's modulus in the range of from 7 to 80 MPa allows for theprovision of stable features having high fidelity and sizes between 10nm and>1 millimeter.

Stable features are obtained when the energy that is gained due toreduction in surface area is lower than the energy that is needed todeform the stamp material permanently.

The stamp layer 100 typically has a thickness within the range of 10 to100 μm. The thickness of the patterned layer 100 preferably does notexceed 100 μm since this may result in higher bending stiffnessresulting in impaired conformal contact. In contrast, if the stamp layer100 is too thin, e.g. when used in a multi-layered stamp structure, itmay be affected by the next stamp layer which usually has a lowermodulus. For example, if the layer is too thin dust particles presentcould punch through the high modulus silicone rubber like material(which has a reduced shear to break value compared to commercial PDMS).

Accordingly, very small features on the substrate surface 104 may beobtained with the present invention without damage or altering of thefeatures thus formed.

Typically, the distance between one feature 101 and another; i.e. thewidth of the recessed region 102 is at least 6 nm, e.g. between 6 and 10nm. Such small recessed regions require a low deformation of thefeatures to contact the substrate, and a high modulus is needed to buildup the energy to release the features again.

If the distance between one feature 101 and another is too wide, thestamps may collapse upon contact with the surface of a substrate. On theother hand, if the features 101 of the stamp layer 101 are closelyspaced, narrow structures tend to collapse together upon contact with asubstrate surface 104 (they tend to collapse even upon release from amaster pattern).

The contact surfaces 103 of the stamp layer 100 form an intimate contactwith the substrate surface 104 regardless if the surface is flat orroughened. Problems associated with stamp and/or feature collapse areeliminated.

The relief features 101 are typically arranged in lines having a widthof e.g. 3 to 30 nm on the stamp layer 100.

In embodiments of the invention, the stamp layer may be used in a stampstructure 200 illustrated in FIG. 2.

The printing device 200 comprises a stamp layer 201 comprising thesilicone rubber like material according to the invention. The stamplayer 201 comprises a plurality of features 202 and a plurality ofrecessed regions 203 in between, as well as contact surfaces 204 whichare to form intimate contact with a substrate material.

The printing device 200 further comprises a deformable layer 205typically formed from a PDMS like material having a low Young's modulus.The low modulus of the deformable layer 204 allows the stamp layer 201to deform and comply to rough and non-flat surfaces without increasingthe pressure on the patterned surface layer 201.

The printing device 200 may further comprise a supporting layer 206,which is typically much stiffer than the deformable and patternedlayers. This supporting layer may be a thin glass sheet which preventsdeformations of the deformable layers 201 and 205. Alternatively, thinplastic or metal sheets may be used.

Although, the stamp layer 201 comprising the silicone rubber likematerial according to the invention has a high modulus, e.g 80 MPa, thestamp still provides a very good conformal contact with a substratesurface.

Accordingly, in embodiments the invention further provides a printingdevice 200 for a printing process comprising a first deformable layer205 onto which a stamp layer 201 is arranged; said stamp layer 201comprising a silicone rubber like material having a Young's modulus of 7MPa to 80 MPa, wherein said patterned surface layer 201 is arranged totransfer a lithographic pattern to the surface of a substrate.

The printing process may be a microcontact printing process wherein anink of any kind of material is first applied to the stamp after whichthe stamp is brought in contact with a substrate in order to transfer atleast part of the applied ink from the stamp to the substrate. Such inksmay for example include but are not limited to curable materials,monolayer forming substances, proteins, or any other biologicalmaterial. Alternatively, the printing process may be an imprinting orembossing process. The relief pattern is than transferred to a substrateby providing a substrate with an embossing material that adopts thecomplementary relief structure when the stamsp relief structure isbrought in contact with it. After curing or hardening of this embossingmaterial the printing device is then removed from the substrate leavingit sith the relief structure that is complementary to the one on theprinting device. This step may be part of a lithographic processemploying further steps such as etching of any kind.

In embodiments, the present invention also provides a method formanufacturing a silicone rubber like material having a Young's modulusin the range of from 7 MPa to 80 MPa, said method comprising:

-   -   providing a composition comprising at least one functional T        branched and/or Q branched (poly)siloxane precursor,    -   adding at least one functional linear polysiloxane to said        composition, incubating said composition at a temperature below        100 degrees centigrade CC.

The chemical reaction taking place during incubating preferably provideschemical crosslinking between the at least one functional T branchedand/or Q branched (poly)siloxane precursor and the at least onefunctional linear polysiloxane to such degree that a silicone networkstructure results that has flexible silicone containing chains withinit.

The term incubating is to be construed as meaning: giving the mixturetime for chemical reaction of its constituents, in particular the atleast one functional T branched and/or Q branched (poly)siloxaneprecursor and the at least one functional linear polysiloxane. Theincubating time or working time; i.e. the time between start of mixingof a composition to be crosslinked and the reaching of the gel point, istypically between 5 and 30 minutes. However, other working times mayexist depending on the conditions used during the incubating period.

In embodiments, the method comprises the step of arranging a pattern inthe silicone rubber like material. Such a pattern may be arranged by anyconventional patterning technique, e.g. etching or stamping from amaster mold.

Preferably, a pattern is arranged by incubating the composition in step(c) on a master mold pattern to effect a stamp layer comprising apattern of features.

The silicone rubber like material is cast on a master mold pattern; i.e.a master material comprising a plurality of recesses defining a mastertool pattern, and the stamp layer, which is complementary to the masteris thereafter released and removed from the master. Typically, thematerial is incubated on the master over night. The materials mayoptionally post cure for about 2-5 more days depending on the desiredhardness of the material. The material becomes harder over time.

Optionally, one or more curing catalysts may be added, e.g. a platinum(Pt) catalyst. A cyclic modulator for the platinum may optionally alsobe present.

Preferably, the composition is incubated at a temperature below 50° C.

This is highly desirable and avoids disadvantages associated with highincubation temperatures. For example, when curing compositionscomprising conventional silicone resins having a high glass transitiontemperature, high curing temperatures are typically required (between150° C. and 400° C.). For several reasons this is not desired. Thermalmismatch between the master, typically patterned silicon or quartz is sohigh that large stresses are built up between the stamp and the masterduring heating and cooling. This can lead to crack formation and damageof features. The thermal expansion coefficient of silicone resins istypically one to two orders higher (Linear CTE˜100 ppm*K⁻¹) thanmaterials used on which the final features will be imprinted (e.g.silicon, quartz). Controlling the magnification error will therefore beextremely difficult.

Preferably, the at least one functional T branched (poly)siloxane isselected from the group consisting of a hydride functional T branched(poly)siloxane precursor, a vinyl functional T branched (poly)siloxaneprecursor or mixtures thereof. Such T branched (poly)siloxane precursormay be represented by the following formulas.

Vinyl functional Q branched (left) and T branched (right) (poly)siloxaneprecursors

Hydride functional Q branched (poly)siloxane precursor (HTS)

In the formula of compound 1 as well as in that of the Hydridefunctional T branched polysiloxane precursor, the three lines extendingfrom the lowest two Si atoms, indicate that these Si atoms are eachconnected to three polysiloxane chains as is the Si atom to the farright in this compound. For the avoidance of doubt, these lines do notindicate ethylenic chemical bonds.

Optionally avaiable Q or T branched siloxanes may include Si—OH groups,as indicated the in figure of Q branched siloxanes. These Si—OH groupscould be disadvantageous as they increase the surface tension and arereactive towards other Si—OH groups which are present on silicon orglass. The Si—OH groups can optionaly reactic with silanes, likemono-chloro-silanes, to attach inert or functional groups. Inert methylgroups could be attachted by adding Cl—Si—[CH3]3 to the compound andletting this react under the formation on HCl, which is removed from thesiloxane mix. Functional groups could be vinyl groups (from e.g.Cl—Si[CH3]2CH═CH2) and would increase the reactivity in the siloxanenetwork and provide added cross linking. Other functional groups thatcould be attached could be fluor (from Cl—Si—[CH3]2-CH2CH2CF3) whichwould lower the surface tension.

The vinyl and/or hydride functionality provides a functional T or Qbranched (poly)siloxane precursor with the ability to form branchedchains resulting in a silicone network structure.

Preferably, the functional T and/or Q branched (poly)siloxane and thefunctional linear polysiloxane(s) are miscible in every proportion. T orQ branched (poly)siloxanes comprising large and bulky organic groups,e.g. phenyl modified T or Q branched (poly)siloxane, are typically notwell miscible with linear methyl siloxanes. Improved miscibilityprovides materials with the effect of the invention. Furthermore,modifications with larger organic groups may lead to worse mechanicalproperties and higher surface tension. This is disadvantageous as smallfeatures thus have a tendency to stick together more easily.

Hence, in preferred embodiments, the at least one functional T or Qbranched (poly)siloxane is a functional T or Q branched (poly) methylsiloxane.

When the vinyl functional Q branched (poly)siloxane component 1 is used,mono-chlorosilanes may be added to passivate the Si—OH group or modifythe system with fluoro end groups.

To further increase the branching of the T or Q branched (poly)siloxaneprecursor, the at least one functional linear polysiloxane is selectedfrom the group consisting of a hydride functional linear polysiloxane, avinyl functional linear polysiloxane or mixtures thereof Such linearpolysiloxanes may be represented by:

Vinyl functional linear (VL) PDMS Hydride functional linear (HL) PDMS

The ratio of m to n of the vinyl functional PDMS is typically in therange of from 20:1 to 10:1 e.g. from 13:1 to 11:1. The molecular weightis in the range of from 800 to 40000 Da, e.g. from 1000 to 30 000.

The ratio of m to n of the hydride functional PDMS is typically in therange of from 1:4 to 1:1. The molecular weight is in the range of from800 to 40000 Da, e.g. from 1000 to 30 000, preferably from 1000 to 20000Da.

In preferred embodiments, the at least one vinyl functional linearpolysiloxane is at least 5% vinyl functional. Typically, the vinylfunctional polysiloxane is 6-8% vinyl functional.

When hydride functional linear polysiloxanes are used, these aretypically at least 30% hydride functional, e.g. between 30 and 50%hydride functional with respect to the silicon atoms in the precursor.These ranges provide a material with a large degree of crosslinking anda silicone rubber like material suitable for use in soft lithography.

Accordingly, the proportion of the vinyl and hydride parts of both the Tbranched (poly)siloxane precursors and the linear polysiloxanes may bevaried; and thus also the degree of crosslinking This allows for themodulus of the material to be tuned to a desired value; typicallybetween 7 MPa and 80 MPa.

Preferably, the ratio of hydride functional linear polysiloxane to vinylfunctional linear polysiloxane is in the range of from 2:10 to 8:10,preferably in the range of from 5:10 to 6:10.

Accordingly, a silicone rubber like material having a high modulus isobtained even at curing temperatures as low as 50° C.

Table 1 below exemplifies the modulus adjustability in preparing thesilicone rubber like material according to the invention by combiningdifferent parts of vinyl and hydride functional T branched(poly)siloxane precursor, and polysiloxanes, respectively.

TABLE 1 Young's modulus variability Vinyl Vinyl part II Hydride partYoung's part I Component HL HL modulus (VL) 1 Component 2 30% 50% HTS(MPa) 1.7 0.5 5.7 1.7 0.3 7.4 1.7 0.25 5.11 1.4 0.3 0.62 12 1.3 0.4 0.6221 1 0.5 0.724 16.1 1 0.5 0.58 21.3 1 0.625 0.65 21.5 1 0.625 0.585 40.51 0.625 0.536 36.5 1 0.625 0.813 28.5 1 0.625 0.585 59.8 1 0.125 0.3750.45 16.3 1 0.706 0.553 80.0 1 0.800 0.585 80.0 All parts are parts byweight. Curing temperature 50° C.

Since the stamp layers may be produced from a master pattern it ishighly suitable for mass production. Furthermore, it is relativelysimple, inexpensive and has a high reproducibility. The patterned layersthus formed may be used in several types of stamp structures orpatterning devices.

The silicone rubber like material according to the present invention maybe used in several applications, such as soft lithography in general,e.g. imprint lithography, phase shift lithography, micro contactprinting etc.

Examples of printing devices are well described in embodiments of WO2003/099463, US 2004/0197712 US 2004/0011231 and the non-prepublishedinternational patent application IB2007/054888, of which the contentsare incorporated by reference. The person skilled in the art will finddetailed description in these references on how to make an imprintdevice that uses a flexible stamping or printing device with a rubberlike material according to the present invention. Such a device will becapable of providing small features to a substrate by using theprinting, microcontact printing, imprinting or lithographic imprintingprocesses described in those references.

While the invention has been illustrated and described in detail in thedrawings and foregoing description, such illustration and descriptionare to be considered illustrative or exemplary and not restrictive; theinvention is not limited to the disclosed embodiments.

Other variations to the disclosed embodiments can be understood andeffected by those skilled in the art in practicing the claimedinvention, from a study of the drawings, the disclosure, and theappended claims. For example, the silicone rubber like material or thestamp layer are not limited to a specific stamp structure, but may beused in any type of stamp or patterning device.

In the claims, any reference signs placed between parentheses shall notbe construed as limiting the claim. The word “comprising” does notexclude the presence of elements or steps other than those listed in aclaim. The word “a” or “an” preceding an element does not exclude thepresence of a plurality of such elements. In the device claimenumerating several means, several of these means may be embodied by oneand the same item of hardware. The mere fact that certain measures arerecited in mutually different dependent claims does not indicate thatthe combination of these measures cannot be used to advantage.

The invention claimed is:
 1. A method for manufacturing a patternedstamp layer comprising a silicone rubber like material having a Young'smodulus in the range of from 7 MPa to 80 MPa, said method comprising:providing a composition comprising at least one functional T branchedand/or functional Q branched (poly)siloxane precursor, adding at leastone functional linear polysiloxane to the composition, incubating thecomposition at a temperature below 100 degrees centigrade, arranging thepattern in the silicone rubber like material, wherein the arranging apattern in the silicone rubber like material is effected by executing,on a master mold pattern, the incubating to effect a stamp layercomprising a pattern of features; and releasing and removing the stamplayer from the master mold.
 2. A method according to claim 1, whereinsaid the composition is incubated at a temperature below 50° C.
 3. Amethod according to claim 1, wherein the at least one functional Tbranched (poly)siloxane precursor is selected from the group consistingof a hydride functional T branched (poly)siloxane precursor, a vinylfunctional T branched (poly)siloxane precursor and mixtures thereofand/or wherein said at least one functional Q branched (poly)siloxaneprecursor is selected from the group consisting of a hydride functionalQ branched (poly)siloxane precursor, a vinyl functional Q branched(poly)siloxane precursor and mixtures thereof.
 4. A method according toclaim 1, wherein the at least one functional linear polysiloxane isselected from the group consisting of a hydride functional linearpolysiloxane, a vinyl functional linear polysiloxane or mixturesthereof.
 5. A method according to claim 4, wherein the at least onelinear polysiloxane is at least 5% vinyl functional.
 6. A methodaccording to claim 4, wherein the at least one hydride functional linearpolysiloxane is at least 30% hydride functional.
 7. A method accordingto claim 4, wherein the hydride functional linear polysiloxane and vinylfunctional linear polysiloxane are used in a ratio in the range of 2:10to 8:10.